Figure 4.

Effects of different concentrations of GB applied on high-throughput plant phenotyping of tomato seedlings under cold stress. (A) Acquisition and processing of hyperspectral data. (B) Classification results of PLS-DA model and PLS-DA model of spectral reflectance before low temperature treatment. (C) The spectral reflectance classification results of PLS-DA model and PLS-DA model on the 6th day of low temperature treatment (0.5 was taken as the threshold value, WR and WL categories were set as the value 0, GR and GL categories were set as the value 1, and the y-coordinate was the predicted value of the model for the category values; The closer the predicted value was to the set value, the better classification effect was and the higher distinction between the two categories). (D) NDVI biomass growth status. (E) SIPI. (F) CRI1. (G) CRI2. (H) PSNDa. (I) PSNDb. In all cases, the asterisk indicated a significant difference among the groups according to Tukey’s test (**P < 0.01). WR: tomato seedlings treated with water at room temperature; GR: tomato seedlings treated with 30mmol/L GB at room temperature; WL: Tomato seedlings treated with water at low temperature; GL: Tomato seedlings treated with 30mmol/L GB at low temperature.